Effective Degrees of Freedom in Genetic Algorithms and the Block Hypothesis. - Christopher R. Stephens; Henri Waelbroeck (ICGA, 1997)

Schemata as Building Blocks: Does Size Matter? - Christopher R. Stephens; Henri Waelbroeck; R. Aguirre (FOGA, 1998)

Self-Adaptation in Evolving Systems. - Christopher R. Stephens; I. Garcia Olmedo; Jaime Mora-Vargas; Henri Waelbroeck (Artif. Life, 1998)

Learning persistent dynamics with neural networks. - H. Alejandro Ceccatto; Hugo D. Navone; Henri Waelbroeck (Neural Networks, 1998)

Schemata Evolution and Building Blocks. - Christopher R. Stephens; Henri Waelbroeck (Evol. Comput., 1999)

Predicting Healthcare Costs Using Classifiers. - Christopher R. Stephens; Henri Waelbroeck; Susan Talley; Rosario Cruz; Arlene S. Ash (GECCO (2), 2004)

Predicting healthcare costs using GAs. - Christopher R. Stephens; Henri Waelbroeck; Susan Talley (GECCO Workshops, 2005)